Renewable fuse



F. J. FISHER.

RENEWABLE FUSE.

APPLICATION FILIED :uur 12, m9.

Patented Aug. 9,1921.

INVENTOR F/Pfof/P/c/r a. F/SHER H /8 ATTORNEYS UNITED STATES PATENT OFFICE.

FREDERICK J. FISHER, OF SAN FRANCISCO, CALIFORNIA.

. RENEWABLE FUSE.

Application filed July 12,

T 0 all whom it may concern:

Be it known that I, FREDERICK J. FISHER, a citizen of the United States, and a resident of the city and county of San Francisco and State of California, have invented a certain new and useful Renewable Fuse, of which the following is a specification.

The invention relates to fuses and particularly cartridge fuses in which the fusible element may be readily replaced after fusion.

An object of the invention is to provide a cheap and simple cartridge or inclosed fuse, in which the fusible element may be readily inserted.

Another object of the invention is to provide a renewable fuse of the knife terminal or blade terminal type.

The invention possesses other advantageous features, some of which, with the foregoing, will be set forth at length in the following specification where I shall outline in, full, that form of the invention which I have selected for illustration in the draw ings accompanying and forming part of the present specification. In said drawings I v have shown one specific form of the fuse of my invention, but it is to be understood that I do not limit myself to such form, since the invention, as expressed in the claims, may be embodied in a plurality of forms.

Referring to said drawings:

Figure 1 is a perspective view of the fuse of my invention.

Fig. 2 is a longitudinal section through the fuse.

Fig. 3 is an end view of the fuse with the clamp removed.

Fig. 4 is a perspective View of the clamp.

The fuse of m invention is a renewable inclosed or cartridge fuse of the knife terminal or blade terminal type. The fuse shown in the drawings comprises a casing 2, preferably cylindrical in form, and composed of any suitable insulating material such as vitralite, pressed paper or fiber, or earthenware. Secured to each end of the casing in any suitable manner is a metallic ferrule 3 in which is a head 6, having a projecting knife terminal or blade terminal 4.

The terminal is disposed diametrically of the ferrule 3, the head of which is provided with an aperture 5 directly above the terminal. In the construction shown, the head 6 is held in place on the casin by the ferrule 3 which may be threaded, t ereon. The

Specification of Letters Patent.

Patented Aug. 9, 1921.

1919. Serial No. 310,395.

blade 4 extends through the head or projects inwardly from the head into the easing, forming a guide 7 for the replacing fusible element. The fusible element 8 consists preferably of a flat strip of fusible metal, which extends through the apertures 5 in the heads and lies on the blades 4.

Means are provided for clamping the fusible strip 8 to the blades to produce a tight electrical contact. Fitting over each blade is a thin metallic socket clamp 9 which is preferably provided on its inner end with an integral cup 12 which fits over and forms a tight contact with the ferrule. The base 13 of the cup closes the aperture 5 in the head, thereby sealing the casing. The clamp presses the fusible strip tightly against the blade forming a tight electrical contact which is increased when the blades and clamps are inserted in the fuse holder clips by pressure of the latter on the thin walls of the socket clamp. When the fuse is destroyed, the clamps are pulled from the blades, a,new strip of suitable metal threaded through the apertures, and the clamps replaced. 7

I claim:

1. A renewable fuse, comprising a casing, ferrules on the ends of said casing provided with end closures having apertures, a blade secured to and extending longitudinally from the closures of each ferrule, a fusible element extending through said apertures and overlying said blades, and socket clamps for holding said element in contact with said blades.

2. A renewable fuse, comprising a casing,

blades secured to the ends of the casing and extending longitudinally thereof and having within the casing strip-guides, a strip of fusible material extending through said casing and overlying said blades, and clamps for clamping the strip against said blades.

3. A renewable fuse comprising a casing, terminals arranged at the ends of the casing, a fusible element extending through the easing and overlying said terminals and frictional socket clamps pressing the fusible element against the terminals.

4. A renewable fuse comprising a casing, ferrules arranged on the ends of the casing and provided with closed ends having aper tures, blades extending outward longitudinally from the ferrule ends at the bases of the apertures, a fusible strip extending through said apertures and lying in contact with said blades, clamps for pressing the fusible strip against the blades, and flanges on the clamps closing said apertures.

5. A renewable fuse comprising a casing, ferrules arranged on the ends of the casing and provided with closed ends having apertures, a blade extending outwardly from each ferrule end and inwardly and down wardly from the base of the aperture, a strip of fusible material extending through the apertures and overlying the blades, clamps for pressing the fusible strip against the blades and cups on the clamps surrounding the ferrules.

6. A renewable fuse, comprising a casing, metallic ferrules arranged on the ends of the casing and having end closures with apertures, a diametrically disposed blade extending outwardly from each aperture, an extension on each blade lying within the easing and sloping toward the side wall thereof, a thin fusible metal strip extending through said apertures and contacting with the upper flat faces of. the blades, clips slidable longitudinally over the blades to clamp the strip thereto and flanges on the clips overlying and closing said apertures.

In testimony whereof I have hereunto set my hand at San Francisco, California, this 28th day of April, 1919.

FREDERICK J. FISHER.

In presence of 11. G. PnosT. 

